Her problem is not ability to write, creatively or correctly. I don't think it's a motor issue either, as her craft skills are quite good. Maybe its an organizational issue or a processing one? Or is it a rebellion against writing 5 sentances in 10 minutes because they would be "simple" sentances? Like she is unable to make herself do work she considers "too easy"?
Maybe it's just being 8? Fourth grade apparently requires far more writing than 3rd did, and my DD8 has really struggled with it this year. She's physically capable of getting the writing done. When she's writing of her own volition, she writes and writes without complaint. For schoolwork, she stares blankly or goes around and around making fiddly little things perfect while totally failing to make any progress on the main task.
The other day, she was working on writing sentences using her spelling words, and had erased everything on the page and started over so many times that I finally had a screaming tantrum and picked the words for her. ("Valuable. Write a sentence with valuable." *kid writes* "Lovable. Write.") Later that day, she said that having me pick the words was wonderful and could we do the spelling like that every week.
Too many choices to overcome the lack of inherent interest, maybe?
